/*
 * Copyright (C) 2011 by Fabien Barbero
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
package com.flickr.api.auth;

import com.flickr.api.AbstractFlickrService;
import com.flickr.api.ApiKey;
import com.flickr.api.CommandArguments;
import com.flickr.api.FlickrServiceException;
import com.google.inject.Inject;
import java.net.URI;
import java.net.URISyntaxException;
import oauth.signpost.OAuthProvider;
import oauth.signpost.basic.DefaultOAuthProvider;
import oauth.signpost.exception.OAuthException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * http://www.flickr.com/services/api/auth.spec.html
 * http://www.flickr.com/services/api/auth.howto.web.html
 *
 * @author Fabien Barbero
 */
public class AuthenticationServiceImpl extends AbstractFlickrService implements AuthenticationService {

    private static final Logger LOGGER = LoggerFactory.getLogger(AuthenticationServiceImpl.class);
    private final ApiKey apiKey;
    private final AuthenticationServer server;
    private OAuthProvider provider;

    @Inject
    public AuthenticationServiceImpl(ApiKey apiKey) {
        this.apiKey = apiKey;
        server = new AuthenticationServer();
    }

    @Override
    public Caller authenticate() throws FlickrServiceException {
        try {
            server.start();
            getOAuthProvider().retrieveAccessToken(apiKey.getConsumer(), server.getAuthenticationCode());
            
            CommandArguments args = new CommandArguments("flickr.auth.oauth.checkToken", apiKey);
            AuthTokenResponse response = doGet(args, AuthTokenResponse.class);
            return response.getAuth().getCaller();
            
        } catch (OAuthException ex) {
            throw new FlickrServiceException("Authentication error", ex);
        }
    }

    @Override
    public URI getAuthPage() throws FlickrServiceException {
        try {
            String authUrl = getOAuthProvider().retrieveRequestToken(apiKey.getConsumer(), server.getUri().toString());
            LOGGER.debug("Auth page: {}", authUrl);
            return new URI(authUrl);
        } catch (OAuthException ex) {
            throw new FlickrServiceException("Invalid auth page URI", ex);
        } catch (URISyntaxException ex) {
            throw new FlickrServiceException("Invalid auth page URI", ex);
        }
    }

    private OAuthProvider getOAuthProvider() {
        if (provider == null) {
            provider = new DefaultOAuthProvider(
                    "http://www.flickr.com/services/oauth/request_token",
                    "http://www.flickr.com/services/oauth/access_token",
                    "http://www.flickr.com/services/oauth/authorize");
            provider.setOAuth10a(true);
        }
        return provider;
    }

    @Override
    public synchronized void logout() throws FlickrServiceException {
        provider = null;
    }
}
